public class Solution {
/*    public int maxProfit(int[] prices) {
        int n = prices.length;
        int[][] dp = new int[n][5];
        dp[0][1] = -prices[0];
        dp[0][3] = -prices[0];
        for (int i = 1; i < n; i++) {
            dp[i][1] = Math.max(dp[i - 1][1], -prices[i]);
            dp[i][2] = Math.max(dp[i - 1][2], dp[i - 1][1] + prices[i]);
            dp[i][3] = Math.max(dp[i - 1][3], dp[i - 1][2] - prices[i]);
            dp[i][4] = Math.max(dp[i - 1][4], dp[i - 1][3] + prices[i]);
        }
        return dp[n - 1][4];
    }*/

    public int maxProfit(int[] prices) {
        int[] dp = new int[4];
        dp[0] = -prices[0];
        dp[2] = -prices[0];
        for (int i = 1; i < prices.length; i++) {
            dp[0] = Math.max(dp[0], -prices[i]);
            dp[1] = Math.max(dp[1], dp[0] + prices[i]);
            dp[2] = Math.max(dp[2], dp[1] - prices[i]);
            dp[3] = Math.max(dp[3], dp[2] + prices[i]);
        }
        return dp[3];
    }

    public int maxProfit(int k, int[] prices) {
         int[] dp = new int[2 * k];
         for(int i = 0; i < k; i++) {
             dp[2 * i] = -prices[0];
         }
        for (int i = 1; i < prices.length; i++) {
            dp[0] = Math.max(dp[0], -prices[i]);
            dp[1] = Math.max(dp[1], dp[0] + prices[i]);
            for (int j = 1; j < k; j++) {
                dp[2 * j] = Math.max(dp[2 * j], dp[2 * j - 1] - prices[i]);
                dp[2 * j + 1] = Math.max(dp[2 * j + 1], dp[2 * j] + prices[i]);
            }
        }

         return dp[2 * k - 1];
    }
}
